Outside Russia and a small strip of Eastern Ukraine, this weekend so- called referendums there have been roundly ridiculed and criticized as illegal.

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OLEKSANDR TURCHYNOV, ACTING UKRAINIAN PRESIDENT (through translator): That farce, which the separatists call a referendum, is nothing more than propaganda and an excuse for those crimes, awful crimes, such as murder, torture and kidnapping.

AMANPOUR (voice-over): Now even the pro-Russian separatist leader in Donetsk admitted the world would never recognize their vote for independence from Ukraine. On Sunday, pro-Russian separatists in Donetsk and Luhansk organized and counted these ballots, which were printed on a copier with just one question. Neither reports of low voter turnout nor opinion polls showing the majority of Ukrainians, even those in the east, do not want their borders changed.

None of that could prevent the rebels hailing this as a massive victory. And maybe that's because of this. Ballot stuffing, according to pictures that were captured by CNN. Here people are casting more than one vote at a time. E.U. foreign ministers meeting in Brussels promptly slapped a new round of sanctions on Russia, this time targeting companies in Crimea.

But Europe still finds it hard to speak with one voice; France plans to go ahead with a $1.6 billion military contract with Russia. This as NATO's secretary general Anders Fogh Rasmussen tells me in an exclusive interview NATO could take more tougher action to deter Russia's President Vladimir Putin.

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AMANPOUR: Secretary General, thank you. Welcome to the program.

ANDERS FOGH RASMUSSEN, SECRETARY GENERAL, NATO: Thank you.

AMANPOUR: First and foremost, your reaction to these referendums that have taken place in those two districts of Eastern Ukraine.

RASMUSSEN: These referendums are illegal. They are organized in a chaotic manner with dubious and ambiguous questions. So those referendums don't count. The only thing that counts is the presidential election on the 25th of May.

And I urge all actors to make sure that those general elections can be conducted in an orderly manner.

AMANPOUR: What do you think President Putin's next move is?

RASMUSSEN: Well, I'm not going to guess about the Kremlin motives and next steps. But what we have seen so far is a Russian attempt to destabilize the situation in Eastern Ukraine and make the conduct of those presidential elections very, very difficult.

What Russia should do would be to stop supporting the separatists and help make sure that the presidential elections can be organized in an orderly manner.

AMANPOUR: When you analyze all of this, I know you don't want to make predictions, but let's face it; President Putin last week told these regions to postpone their referendum. And they didn't do that.

Do you believe that President Putin has control over this region, over those separatists?

RASMUSSEN: No. I consider that part of a bigger game. Probably it was just to pretend that the separatists act independently of Moscow and obviously Moscow has a strong influence on the separatists.

So no doubt that if Moscow took the decision to encourage separatists to lay down their weapons and let the presidential elections go forward in an orderly manner, that would also happen.

AMANPOUR: The United States has said that they feel that the Moscow game is to landlock Ukraine. Now this is a military strategic question. So that's why I'm putting it to you.

Do you believe that they are in a position to move around to Odessa, to landlock Ukraine, maybe even to go into the Transnistria region of Moldova?

Do you assess that that is what they're thinking about?

RASMUSSEN: Well at least they have the capacity to do so. They have massed armed forces along the Ukrainian borders, 40,000 -- around 40,000 troops. And in addition to that 25,000 troops in Crimea.

We have seen that Russia is able to -- or the Russian armed forces are able to act within a few hours if the political decision is taken. What I don't know is whether the political decision has been taken or will be taken. But at least they have the capacity to do that.

AMANPOUR: Do you see any evidence of what President Putin said he was doing and that is redeploying, moving back 40,000 Russian troops from the border?

RASMUSSEN: Not at all. We haven't seen any visible evidence of a Russian withdrawal from the borders. And we have seen such announcements in the past as well without any withdrawal of Russian troops. So we are very cautious when it comes to such announcements.

AMANPOUR: Now many people have said, OK, these sanctions are gradually being ratcheted up; Europe is considering another round of sanctions. But are they really hurting the Russians? Many people say NATO has at its disposal the ability to put more ground forces in more NATO countries, closer to Russia?

Why doesn't NATO do that, send a clear and unquestionable signal to President Putin, who's clearly testing you all the time?

RASMUSSEN: Actually, we have done that. We have taken steps to reinforce our collective defense through enhanced air policing over the Baltic States, deployment of AWACS airplanes over Poland and Romania to improve our surveillance. You have seen more naval presence in the Black Sea as well as the Baltic Sea.

And we arrive now, considering possible further steps to reinforce a collective defense.

So we have sent a very clear message of reassurance to our allies and a very clear message to Moscow as well.

AMANPOUR: Of course, the allies say they'd like to see a little bit more, if not reassurance, heft. I don't know what you think, but 150 U.S. soldiers to Poland?

I mean, is that really enough to tell Mr. Putin, who's got 40,000 troops massed on the borders there, to step back?

RASMUSSEN: Well, as I told you, we are right now in the process of considering further steps. Those further steps might include an update of existing defense plans, development of new defense plans, enhanced exercises and also appropriate deployment.

However, it's a bit too early to tell exactly how to do it and where to do it, but we will not hesitate to take further steps if needed.

AMANPOUR: Can I move on to Afghanistan, Mr. Secretary General, because today the Taliban has announced that they have launched their spring-summer offensive, right on target, as they said they would. And they've attacked NATO targets today.

How worried are you at this convergence of a NATO withdrawal and a Taliban uptick in military activity?

RASMUSSEN: Yes, but there's nothing new in that. The fact is that the Taliban failed to disrupt the presidential election, the first round of the presidential elections in April. And that was a clear blow to the Taliban and other enemies of Afghanistan.

And it also reflects that the Afghan security forces are very capable of dealing with the security situation in Afghanistan so I'm confident that the Afghans will be able to take full responsibility for the security by the end of 2014 as planned.

AMANPOUR: Except for that during these elections, there were tens of thousands of NATO forces to actually help protect the elections and the balloting. And the international crisis group today has a report that says you're quite right; this is nothing new.

But the entire past year as NATO has been gradually pulling down, Taliban attacks, deaths, all those kinds of things have been going up.

So again, you must be worried, aren't you? And if not, why not?

RASMUSSEN: Of course we are alert. But the fact is that the Afghan security forces took the lead in ensuring a secure environment for the conduct of presidential elections and they will continue to be in the lead.

Yes, we are there to support them. But they have taken the lead for security operations and actually we have seen them address that in a very professional manner.

So we expect the Afghan security forces to take full responsibility by the end of this year as planned. And then we will establish a training mission to continue to train, advise, assist the Afghan security forces after 2014.

AMANPOUR: Because you know you'll get that agreement from whoever is the next president?

RASMUSSEN: I'm confident that we will get a signature on the necessary security agreements.

AMANPOUR: Secretary General Rasmussen, thank you very much for joining me.

RASMUSSEN: You're welcome.

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AMANPOUR: Confidence there, perhaps buoyed by what the frontrunner in the presidential race, Abdullah Abdullah, told me back in February when he pledged to sign a security agreement with the United States to enable troops to remain. And he has now secured the backing of the third place candidate, Zalmai Rassoul, who was foreign minister, as part of his efforts to win the presidential runoff election next month. And you can watch my interviews with both those candidates online at amanpour.com.

Now Afghanistan is battling an all-time high opium harvest as well, despite Washington spending billions to combat it. Targeting the traffickers and battling big tobacco, my next guest takes this message to the White House today, the most unusual style of Uruguay's president when we come back.

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AMANPOUR: Welcome back to the program.

President Obama welcomed Uruguayan President Jose Mujica to the White House today. Now the U.S. presidential dwellings look a bit different than the Uruguayans because Mujica has foregone all the trappings of power and he lives here in his own tiny home on a dirt road in the capital, Montevideo.

Mujica's austere lifestyle has grabbed the world's attention since he became president in 2010. He drives a 1987 Volkswagen Beetle; he donates 90 percent of his salary and he sells flowers that he grows with his wife, who is, by the way, a senator.

But it's Mujica's remarkable transformation from Marxist guerilla to president and his country's liberal laws, especially on marijuana, that have thrust him into the spotlight now.

Uruguay is the first country to fully legalize the marijuana trade, earning it both praise and criticism from all over the world. Ironically, Mujica is also battling big tobacco, and he wants Obama's help, he told me just before their meeting. He's bringing his own goodwill, too, reiterating his offer to accept some of the Guantanamo prisoners, to help close what he calls "that abominable place."

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AMANPOUR: President Mujica, welcome to the program and thank you for joining me.

AMANPOUR: Let me first start by asking you about legalizing marijuana in Uruguay.

What is the reaction to the legalization of marijuana in your country?

MUJICA (through translator): It's not legalization; we are regularizing a clandestine market that we want to legalize that a market state is going to take charge. We are not expanding addiction. We are trying to resolve the problem in time for people who go into this addiction, which, like any other addiction, is a bad thing.

In my country there is a majority of people who do not understand my policy yet. However, the popularity of it has been climbing up. More people are now understanding what it's all about.

It is a measure against traffic, drug dealing. We are trying to snatch the market away from them because it's 80 years now that we are repressing drug use. And in '84 we had about 2,000 registered consumers; today we have 150,000.

So like everywhere in the world, repression by itself doesn't do the job. We are trying to find another way.

AMANPOUR: This is gaining traction, even in the United States.

But what do you say to critics who are worried that it'll encourage young people, for instance, to start earlier and therefore become addicted?

MUJICA (through translator): We think we're going to get the exact opposite effect.

Now when you surround that with this forbidden aura, you are actually calling the young girl to take it up.

However, if you place it as a controlled product that you can purchase at the chemist, like some other drugs like morphine, which is used for certain prescriptions, then we are taking the mystery out of marijuana and we hit the drug dealers.

AMANPOUR: You were the leader of the Tupamaro guerillas in Uruguay for many years. And at that time, there was a deep anti-Americanism obviously amongst the rebels.

You're president of Uruguay, how you feel about the evolution that here you are now going to the White House, I want to know how you feel.

MUJICA (through translator): I cannot deny reality. I don't know whether I like this planet or not. But I have to accept it. It would be disingenuous for me if thinking that if a small country like mine ignores what the United States is today, there is not just one United States.

There are a lot of things in the States that I could consider to be reactionary of invasive attitudes, things that sometimes are even scary because of the amount of power this country has in response to Latin America.

However, there's also a big debate in the States. There's a human progress. There's a technological and scientific development that helps the whole of humanity.

So we cannot just put everything in one bag and just say one word to describe the U.S. The States is an amazing place. The president might be a bit restricted by Congress, but a lot of us -- and I will say it like this, we never thought that a black person would actually get to power in the United States. So that's a battle won.

AMANPOUR: Mr. President, you have captured the world's imagination because you are known as the world's poorest president. In fact, you choose to live in your original residence of your own. You won't go and live inside the presidential palace.

Can you tell me what it is that motivates you and how your 14 years in jail affects the way you live today?

MUJICA (through translator): My years in jail were a bit like a workshop for my -- that actually forged my way of thinking and my values. I'm not a poor president. Poor are the people who need a lot and that was -- Seneca said that.

I am an austere president. I do not need much to live. I live in the same way I used to live when I wasn't a president and in the same neighborhood, in my same house and in the same way. And I am a republican. I live like the majority in my country lives. It was a majority who voted for me. And that's why I identify with them.

Morally, I do not have the right to live like a minority in my country. A lot of people like a lot of money. They shouldn't go into politics. That's my way of seeing it. I am not improvising. I'm not -- I don't do marketing. This is my philosophy.

AMANPOUR: How long did you spend in solitary confinement?

And how did you manage to survive that?

MUJICA (through translator): Because human beings are strong. And that's what I want to transmit to people, that we can trip and fall, but we can always stand up and start anew. We shouldn't look for that strength outside. We have it inside ourselves. We shouldn't blame others. We have to look inside ourselves for that strength. Nature has given us all we need.

The ones who fail are those who stop fighting. Life is a lovely fight. We have to defend it.

And that's something I came to ask President Obama. We have a fight against tobacco. Eight million people die a year by smoking. That's a lot more than all the people who dies at wars.

AMANPOUR: Philip Morris is suing Uruguay because of your actions against smoking and against tobacco.

What is your response to that?

MUJICA (through translator): I have said it already. I -- it's not about companies; it's not about suing. I am just asking that we do have to really fight against this. Life is worth everything and we have to fight for it. Being alive is a miracle and I will really insist every day.

That's why this battle against tobacco and other battles for life, I will always fight for them.

AMANPOUR: I just want to ask you finally to explain how you survived what you did to get through 10 years in solitary confinement. I read that you interacted with the insects and befriended the rats in your cage.

Why was that important?

MUJICA (through translator): If you catch a black ant, a normal common ant, you rub it with two fingers, you put her right inside your ear, and you hear it scream. But of course you need time to do that. And you have to be really lonely.

When you spend a long time by yourself in solitary confinement, a frog, a rat that comes to eat because you leave some crumbs there, it's life. It's the life you have there. And probably there's nothing worse than loneliness after that. We are gregarious. We need society to live. We never save ourselves alone. We always save ourselves with the others.

These are very elemental things of life. Yet they're things that we forget too often.

AMANPOUR: Mr. President, Jose Pepe Mujica, you've had an incredible journey and you have an incredible story. Thank you very much for joining me.

MUJICA (through translator): Thank you so much.

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AMANPOUR: And turning now to the shocking plight of those lost girls of Nigeria, video released by Boko Haram purports to show some of them, sitting in the open, veiled from top to toe, reciting bits of the Koran after apparently being forced to convert to Islam.

The group's leader says he's willing to trade the girls for Boko Haram prisoners. The video raises painful questions about what they have already been forced to endure four weeks after being captured.

Offers of help have come from the United States, Britain, France and China, although it's not clear whether Nigeria has accepted or not. Israel has also offered to send in a team of counterterrorism experts to assist in the search.

And when we come back, a centuries' old story of anti-Semitism in Spain is once again in the news. We'll explain next.

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AMANPOUR: And finally tonight, as we're witnessing in Nigeria and Afghanistan and other parts of the world, terror and religious brutality are all too familiar today. And echoes of the past atrocities are never far away, either.

So imagine a world where the anti-Semitic name of a Spanish village might once have saved hundreds of Jewish lives. The village is called Castrillo Matajudios, which translates roughly as "the little hill fort of the Jew killers." Not surprisingly, the town's mayor thinks a name change is in order now. But the villagers, about 5 dozen in all, are reluctant to change a name that served for centuries.

There are Jewish historians in Spain to trace the name back to its roots and they found a surprising explanation. In the Middle Ages, Castrillo Matajudios was a flourishing Jewish community. In fact, it seems the town was originally called Castrillo de Judios, Fort Hill of the Jews, which could explain the Jewish star in the village seal.

But when Jews were expelled from Spain in 1492 during the horrors of the Spanish Inquisition, Jews there converted en masse to Catholicism. They took the name Jew killers as protection to prove their religious bona fides to their neighbors. Residents of Matajudios vote on the name change next week. And people in the town of Matamoros are watching with interest.

"Matamoros" means "Arab killer," a relic of Spain's long war against the Moors of North Africa.

And that's it for our program tonight. Remember you can always contact us at our website, amanpour.com, and follow me on Twitter and Facebook. Thanks for watching and goodbye from London.